The invention relates to machinery for pre-spinning treatment of fibres and, more particularly, it relates to sliver placing devices or coilers for draw frames and like machines.
The invention can be used to utmost effectiveness in high-speed draw frames with sliver delivery rates as high as 220 to 410 m/min, for feeding open-end spinning frames.
Prior Art
At present, known in the art are draw frames incorporating a device for placing the sliver into a can, commonly called "the coiler," including a movable bottom vertically reciprocable in the can. The bottom is reciprocated by a mechanism made in the form of a vertical rod which lowers to 1.5 m below the floor level within a can-filling cycle.
To control the sliver-placing or coiling density, the known machines include system of counterweights operatively connected with the vertical rod. However, the incorporation of these systems complicates the erection of a machine, and also its operation and maintenance.
In the industry there are also known draw frames with coilers wherein the reciprocation of the movable bottom is effected by means of a pantograph mechanism accommodated within a vertically extending drum of which the uppermost end face supports the can. However, this requires either reducing the height of the can proper or increasing the overall height of the draw frame, e.g. to 2,120 mm, which considerably hampers the operation and maintenance of the drafting device of the machine.